This invention is directed to the art of metal removal or cutting tools and more particularly, to an indexable insert type drill.
There has recently been a substantial interest in drills having cutting edges defined by indexable and/or replaceable inserts formed from carbide and the like. Typical of some of the more recent innovations for such drills are the arrangements shown in the commonly assigned U.S. Pat. Nos. 4,072,438 and 4,131,383 to Powers.
In conjunction with these prior development efforts, it has been found desirable to develop an indexable insert drill particularly adapted for use in cutting soft metals such as aluminum or the like. At the same time, it has also been found desirable to provide such a drill with convenient means for fixedly retaining an insert in a drill body insert receiving pocket to provide greater insert stability during actual machining operations. In addition, it has been deemed advantageous to provide inserts which have at least two cutting edges so that when one cutting edge is worn or otherwise ineffective, the insert may simply be removed from the associated drill body, inverted or otherwise indexed and reinstalled with a new cutting edge disposed in cutting presentment. Along with this latter feature, it is considered advantageous to be able to provide means for protecting the second or alternate cutting edge from damage when it is in a stored or position of non-use.
The subject invention is deemed to meet the aforementioned needs and provides a new and improved indexable insert drill and insert which facilitates improved machining results for soft materials such as aluminum and the like when the drill is used in either the dynamic condition (drill rotating) or the static condition (work rotating).